The other day I was reconfiguring a network with multiple PCs, wireless access points, bridges, and the like. In the midst of this, I noticed that one of the PCs had a “page could not be displayed” message instead of the site being visited, which was amazon.com. Google’s site came up fine, but not amazon. I went to another PC - same issue. There is a great resource for this situation - www.downforeveryoneorjustme.com. I tried it and sure enough - www.amazon.com was not reachable! The outage only lasted a brief while, I saved this screenshot for posterity. Next time you have trouble reaching a site, why not see if others are having the same problem?